Integrated circuit (IC) packages are typically comprised of an insulated housing with a plurality of lead connectors extending outwardly from the housing. One common IC package is the dual in-line package (DIP) in which electrical leads are brought out along two sides of the housing. Another common IC package is the quad flat package (QFP) in which the leads are brought out along four sides. Another package design is the ball grid array, where the lead connectors extend from the bottom of the IC. As IC's get larger, with a corresponding increase in the number of connections needed between the IC and the PC board, the IC package designs that only use the edge of the IC for connections are less desirable. Some of the disadvantages of the IC package designs that use only the edges for connections are the limited space available along the edges and the length of the traces from the IC to the PC board. The ball grid array package design overcomes these limitations by using the area underneath the IC package as the place to route the lead connector between the IC and the PC board.
Electronic test equipment (e.g., oscilloscope, logic analyzer, and emulator) is used to analyze various electrical aspects of the IC including voltage and current waveforms. Typically, a loaded printed circuit board is crowded with various electrical components, including multiple IC packages. Due to the close spacing of components on the board (i.e., high "board density"), as well as the small size and pitch of each IC package lead, it is often difficult to manipulate each lead with a test probe to electrically connect each lead to the test equipment. This problem of electrically connecting to the IC leads is made impossible for the ball grid array package because many of the signals are hidden under the IC package after the IC package is mounted onto the PC board. There is a need to probe the signals coming from an IC packaged in a ball grid array.